Compressor mechanism



Dec. 10, 1935. w. FOURNESS COMPRESSOR MECHANISM Filed Nov. 4, 1932 2, Sheets-Sheet 1 INVENTOR l4///Z0 F as BY ATTORNEY Dec. 10, 1935.

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COMPRESSOR MECHANISM 7 Filed Nov. 4, 1932 2 She.etsSheet 2 by, l I

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. INVENTOR 77 m/f/"qc/ F rxmss 7 ATTORNEY Patented Dec. 10, 1935 PATENT OFFICE COMPRESSOR MECHANISM Wilfred Fourne'ss, Oakland, Calif.', assignor, by mesne assignments, to Edward G. Burghard,

- New York, N. Y.

Application November 4, 1932, Serial No. 641,248

5 Claims. (01. 230-206) This invention relates to a mechanism for compressing a fluid refrigerant for use in a mechanical refrigerating system.

An eflicient compressor mechanism utilized in this manner has been described and claimed in my prior application, SerialNo. 572,952, entitled Compressor system and filed November 4, 1931. The present application is a continuation in part of this prior application,

In that prior application, the compressor mechanism is enclosed in a casing that is fluid tight, and that carries a lubricant in which the mechanism is at least partially submerged; The compression is secured by the aid of pistons reciprocating in cylinder blocks. In order to provide a compact mechanism, the piston rods are directly connected to the crank or driving shaft, without any intermediate connecting rod, and the cylinder blocks are permitted to oscillate to compensate for the varying angularity of the piston rod as the driving shaft rotates. I

In the prior application, the interior of the casing is kept at a pressure substantially the same as that of the intake, by the aid of an equalizing connection between the interior of the casing and the intake port of the compressor. The mechanism furthermore is such that during the starting period, the outlet ports of the cylinders are in communication with the interior of the casing, whereby the starting load is reduced to a desirable value. This is accomplished by so arranging the oscillating cylinder blocks that they are urged into operative relation to a discharge conduit leading from the casingby the aid of outlet pressure. Since this is all fully described in the said application, further description thereof is considered unnecessary.

With the interior of the casing subjected to intake pressure, there is no pressure available to urge the oil between the sliding parts of the mechanism. It is one of the objects of this invention to make it possible to force the lubricant into the various cylinder chambers for effective lubrication.

In case the refrigerating system is operating to reduce the temperature very greatly, it is likely that the intake pressure at the compressor is considerably below atmospheric. Under such circumstances, the interior of the casing has the same reduced pressure. Thus the air from outside the casing has a correspondingly higher pressure which tends to transmit air into the casing past the seals provided around the operating shaft. It is another object of this invention to preven this occurrence.

These objects are accomplished by ensuring that the pressure in the interior of the casing is always slightly above atmospheric or slightly above intake pressures. This result is attained quite readily by introducing into the equalizer conn'ection from the suction or intake port into the casing, a spring loaded valve that is so set that it will not permit escape of gas from the casing into the intake port until a definite higher pressure is reached. In most instances, a very 10 small pressure differential, such as one pound, is sufficient to accomplish the results desired, so that the interior of the casing is maintained nevertheless substantially at intake pressures.

This invention possesses many other advan- 5 tages, and has other objects which may be made more easily apparent from a consideration of one embodiment of the invention. For this purpose there is shown a form in the drawings accompanying and forming part of the present 20 specification. This form shall now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention 35 is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a side elevation, partially in section, of a compressor mechanism embodying the invention; 30

Fig. 2 is a cross section'taken along the plane 22 of Fig. 1; with the addition of diagram.- matic elements illustrating the refrigerator system; Fig. 3 is a cross section taken along plane 3-3 35 of Fig. 1; and

Fig. 4 is a fragmentary sectional view taken along the plane 44 of Fig. 2.

In view of the disclosure of the compressor -mechanism in my prior application, Serial No. 40

572,952, it is considered unnecessary to describe this mechanism in great detail. In general the compressor comprises a fluid tight casing I, supported appropriately by the aid of feet 2. This fluid tight casing is formed most conveniently 45 by the aid of a central partition or wall 3 to which are appropriately fastened the cover members 4 and 5. A horizontal shaft 6 for operating the compressor mechanism proper extends through appropriate sealing devices I and 8 in 5 the opposite walls of the casing. This shaft can be appropriately driven from any source of power, as for example, by an electric motor.

Intake and discharge passageways 9 and I0 respectively pass from the outside of the com- 55 by the compressor mechanism passes from the discharge passageway III to the refrigerating system, where it is first condensed, and then vaporized for the absorption of heat. The va-.

porized gas is then returned to the suction or intake passageway ,l.

I On each side oi the central partition or wall 3 is supported a saddle I2 having a cylindrical inner surface I3. Each saddle I2 accommodates a valve block I4 and a piston block II (Fig. 4) These blocks accommodate, respectively, the piston valve I6, and main piston ll. The valve I6 and the piston I1 are both driven from the shaft 6 by the aid of the eccentrics I8 (Fig. 2) and I9 (Fig. 3), respectively. The phase relationship between the valve I6 and piston II can be the same as in any prior application and in general the construction of these parts are identical with that disclosed in that application.

The valve blocks I4 are disposed respectively on opposite. sides of the partition 3 as shown most clearly in Fig. 4, through which there may be apertures, such as 20 (Fig. 2) in order that the pressure inside 'of casing I may be uniformon both side of'partition 3.

The inlet passageway 8 communicates with a cross passageway 2! extending through the partition 3, and communicates with ports 22 and 23 in the saddles I2. These ports respectively are in communication with the interior of the cylinder 24 in the valve blocks I4. The outlet or discharge port I similarly communicates with a passageway 25 also communicating with both of the cylinders in the valve blocks II. The main piston block I is in communication with the interior of the valve block as by way of the passageway 26. i

It is apparent that upon rotation of the shaft 6, the piston valve It serves alternatively to connect the cylinder block with the intake and discharge passageways.

As indicated in Figs. 1 and 2, a body of lubricant 35, such as oil, may be enclosed in the casing I, and may have a level corresponding to about the center of the apparatus. Furthermore as in my prior application, an expansion bellows or sylphon 21 may be provided and subjected to discharge pressures for urging the blocks I 4 and I5 together during normal operation of the compressor. When the compressor is standing still, these cylinder blocks are permitted to separate, and therefore, during the starting period, the compressor is unloaded, because the suction and discharge passageway ports are in communication with the interior of the casing I through the space between the two blocks. In Fig. 1, a connecting pipe 28 is indicated for leading gas at outlet pressures to the sylphon 21.

A connection is also provided between the suction or intake passageway of the compressor and the interior of the casing. For this purpose one of the saddles I2 is provided with a boss 29 having a general right angled configuration and having a passageway connecting to the ports 22 and 23. This passageway is connected by way of a pipe ll to a valve 2| which will be hereinafter described. This valve 3| in turn communicates with a right angled aperture in the partition 3. Into this aperture from the outside is fastened a pipe 32. This pipe 32 is enclosed in an equalizing chamber by the aid of a casing 33 fastened to the top of the partition 3. This equalizing chamber is in communication with the 5 interior of the casing I by way of an aperture 34 communicating with one of the apertures 20 in the wall 2.

The valve 3| is an adjustable spring loaded valve which restricts the passage of gas, which is in the casing I above the body of lubricant 3!, until the pressure of said gas is slig tly above suction pressure, but considerably be ow the dis charge pressure. The'arrows in Figs. 1 and 2 show how this gas can flow through this spring loaded valve when the pressure is sufllcient, to the suction side of the compressor.

By adjustment ofthe valve 3|, it is thus possible to maintain the pressure inside of the casing one or two pounds above that of the suction g pressure. In this way, the pressure inside of the casing being substantially at suction pressure, will ensure that the compressor will be unloaded during the starting period; andyet at a slight pressure differential, sufficient to'force the oil 25 through appropriately formed oiling passageways that maybe provided; for example, such 88 passageway 36 leading from the interior of the casing to the interior of the valve block I4. The oil can also pass from the valve block into the main cylinder via the cylinder ports.

Furthermore, should the refrigerating system operate at extremely low temperature, in which case the suction pressure may be below atmospheric, the spring loaded valve 3I may be so ad- J'usted as to maintain the pressure inside of the casing slightly above atmospheric pressure. In this way, any tendency for air to leak into the casing from the outside is obviated; and the various sealing devices around the entry of the 40 shaft 6 are not subjected to any pressure strain.

I claim:

1. In a device of the character described, a fluid tight casing, a compressor mechanism in said casing, means forming an inlet passage to the compressor mechanism, means whereby during the starting period, the compressor mechanism discharges into the casing, and means whereby during running period, the pressure in the casing is maintained considerably below outlet pres- 5 sure but slightly above intake pressure.

2. In a device of the character described, a compressor mechanism having a slide valve mechanism, a casing enclosing the compressor mechanism, a lubricant in the casing, said valve mechanism having a passage to admit lubricant thereto during the suction stroke of the compressor mechanism, and means for maintaining the pressure in the casing considerably below the discharge pressure and slightly above intake pros- 0 sure.

3. In a deviceof the character described, a reciprocating compressor mechanism having a suction and a discharge stroke, a casing enclosing the compressor mechanism, a lubricant in 55 the casing, said mechanism having a passage from below the level of the lubricant which is open during at least part of the suction stroke, into the mechanism, and means for maintaining the pressure in the casing considerably below the 7 discharge pressure and slightly above intake pressure.

4. In a device of the character described, a reciprocating compressor mechanism having a suction and a discharge stroke, a casing enclos- 7 ingtheoommesscrmechnnimmlubricantinthe cssing said mechanism having a pnssageirom below the level of the lubricant which k open during at least part 01' the suction stroke, into the mechanism, means whereby during starting period, the compressor discharges into the casing, and means for maintaining the pressure in the casing considernbly below the discharge pressure and slightly above intake pressure.

5. The combination as set forth in claim 2, in which the means for maintaining the pressure in thecasing,issoarrangedthatthispressureis 5 slightly above atmospheric.

WIIJ'REDFOURNESS. 

